Wastewater and sewage disposal systems are designed to disperse wastewater and/or effluent discharged from a wastewater storage system or septic tank into an absorption field. For example, the effluent discharged from a septic tank is conventionally directed first into a standard effluent distribution box. The distribution box is intended to divide the flow of effluent into separate, reasonably equal quantities of effluent which then pass through separate discharge pipes for distribution in the absorption field. This division of effluent prevents overloading in a single discharge pipe. Unequal discharge of effluent in a single discharge pipe can result in disproportionate effluent loading in one of the discharge pipes which can saturate the soil in one location while other locations receive only minimal effluent.
Conventionally, distribution boxes contain a single sump, but may have a number of discharge pipes, each of which directs an allocated portion of the effluent into different locations in the absorption field. Each of the discharge pipes in the distribution box must be set at exactly the same depth to achieve distribution of equal quantities of effluent into each of the discharge pipes as water seeks its own level. If the discharge pipes are set at different depths, effluent entering the distribution box tends to flow out of the discharge pipe which is located at the lowest level in the distribution box even if the difference in elevation among the discharge pipes is minimal. Even recognizing the need to maintain the discharge pipes located within the distribution box at the same depth, it is often difficult to install the discharge pipes perfectly level within the ground. In addition, even if the discharge pipes are properly installed, it is difficult to maintain them in a perfectly level position because of settling of the ground and other naturally occurring events.
A number of discharge systems have been proposed to solve this problem of equalizing the flow of effluent out of a distribution box. For example, U.S. Pat. No. 4,298,470 discloses a sewage septic system which includes a septic tank (14) and a distribution box (20), wherein the piping (26) for the effluent in the distribution box (20) includes a liquid leveling cap (34) containing an effluent opening (40). The level of these openings (40) in the caps (34) can be adjusted to accommodate different effluent levels of the piping within the distribution box (20).
U.S. Pat. No. 3,497,067 discloses a distribution box (10) used in conjunction with a septic tank absorption field system to control the relative flow of septic tank effluent among separate discharge pipes (18). In this system, a flow divider, or partition (19), is provided in a lower portion of the distribution box (10). This flow divider (19) has an upwardly projecting knife edge (20) designed to divide the flow of effluent entering the distribution box (10) into separate, generally equal quantities, regardless of the level of the discharge pipes (18) in the distribution box (10). An improvement on this system is disclosed in U.S. Pat. No. 4,605,501. In this system, the flow divider (26) is designed with a particular shape which fits within the discharge pipes (14).
An additional improvement on this system is disclosed in U.S. Pat. No. 5,098,568. In this system the distribution joint (18) contains two or more distribution lines (16a and 16b) leading to separate adsorption fields. A flow divider (24) extends across an outlet line (22) in the throat area where the distribution lines (16a and 16b) join. A cylindrical control sleeve or flow director (26) is rotatably mounted inside the effluent line (14) and is used to direct the effluent into the respective distribution line (16a and 16b).
U.S. Pat. No. 4,838,731 discloses a pivotable tray (26), which is installed within a distribution box (12). The effluent from the septic tank flows into this pivotable tray (26) where it collects until its weight causes the tray (26) to pivot and discharge effluent among various discharge outlet pipes (52).
U.S. Pat. No. 5,322,387 discloses a complicated distribution system for equalizing the flow of fluid through a sewage disposal system.
U.S. Pat. Nos. 5,107,892, 5,154,353 and 5,680,989 disclose a cap that is placed on the end of piping present in a distribution box. Each of these caps contains a weir, which is designed to equalize the flow of effluent out of the discharge pipes of the distribution box.
U.S. Pat. No. 3,956,137 discloses a sewage septic system which contains a plurality of discharge lines (23, 24). The flow of effluent in each of these discharge lines may be controlled by a separate gate valve (26, 27), each of which permits full flow, partial flow or no flow through its respective discharge line.
The present invention is designed to distribute effluent equally among several discharge pipes and represents a significant improvement over the previous products. It includes a distribution system designed to equalize the flow of effluent from a septic tank system into discharge pipes, even when the quantity of the effluent entering the distribution box is very low.
Under normal conditions, the flow of effluent from a septic tank into a distribution box typically occurs in small quantities. This is due to the effect of small quantities of wastewater entering a large septic tank. The typical quantity of wastewater entering a septic tank is no more than about 5 gallons, and frequently less than 1-2 gallons. Each such discharge into the septic tank results in only small, slow pulsing discharges of effluent out of the septic tank to the distribution box. With this slow flow of effluent into the distribution box, even minor differences in the relative position of the effluent discharge piping in the distribution box results in a disproportionate flow of the effluent into one or more of the discharge pipes out of the distribution box. The use of weirs does not completely solve this problem with low flows of effluent. With such low flows, once the surface tension is broken on one outlet pipe opening, the effluent will continue to flow only out that outlet pipe until the surface tension on other outlet pipes is also broken.
Accordingly, it is an object of the invention to provide an improved product for distributing effluent from a septic system in generally equal quantities into multiple discharge pipes.
It is a still further object of the invention to provide a system which equalizes the flow of effluent out of a distribution box.
It is a still further object of the invention to disclose a system for splitting the flow of effluent entering a discharge box into a number of different sumps, each with a separate discharge pipe, even under low flow conditions.
It is a still further object of this invention to utilize a ramp system contained within a low capacity liquid flow splitting system to spread the flow of the effluent across the low flow splitting system.
It is a still further object of the invention to utilize a series of slots in the ramp system to equalize the flow of effluent into separate discharge pipes.
It is a still further object of the invention to utilize a plurality of capillary grooves in the slots in the ramp system to equalize the flow of effluent into separate discharge pipes.
It is a still further object of the invention to utilize a high capacity liquid flow splitting system in conjunction with the low flow system to equalize the flow of effluent into separate discharge pipes.
It is a still further object of the invention to provide an adjustment system for adjusting the relative position of the liquid flow splitting system within an effluent discharge system.
These and other objects of the invention will be apparent from the effluent distribution system disclosed by the present invention.